Alan Journet is a retired ecologist and conservation biologist who is concerned about the future if, he says, "we do not address climate change."

Journet recently moved from Ashland into an energy-efficient passive and active solar house he built on 20 acres south of Jacksonville. His new home has a target of net zero energy use from the grid.

He will give a free lecture from 1 to 3 p.m. today at the Osher Lifelong Learning Institute Ashland campus on how science has led to a better understanding of the world.

He studied entomology in Canada and performed his post-doctoral studies in Australia before teaching biology in the United States while conducting conservation research in the Midwest and the Costa Rican tropics.

What is one fact you want to make clear at today's presentation? The way scientists develop and assess opinions is different from the way politicians do it.

Can you give a few examples of this? In general, folks with everyday opinions and politicians seek evidence that supports their view. Thus, if you think all guns should be available to anyone, you will seek anecdotes about how individuals have used their guns to protect themselves or someone else.

If, on the other hand, you think assault weapons should be controlled, you'll seek stories about how they have caused mayhem or failed to afford protection.

By contrast, the scientific approach is to erect a clear hypothesis about the effectiveness or not of weapons and set up or seek situations that might deny the hypothesis.

You will also talk about scientific exploration. What is its purpose? The essence of scientific exploration is the erection and testing of hypotheses addressing natural laws or patterns in the world around us.

Explain that a little more: Science can only undertake tests of phenomena that are measurable. That means we have to be able to record data from them. If there are no data that we can record, we cannot test the idea.

For example, the claim "I love you more than you love me" or "I am prettier than you" is untestable since there is no way we could identify what data should be collected to test it. On the other hand, "I am taller than you" is clearly amenable to a test of measurement.

You also say that "certainty is not an outcome of scientific research." Can you explain this? Sorry, this one is rather more difficult to exemplify. But there are two major reasons. The first is that when we erect and test a hypothesis, we might find data consistent with that hypothesis for reasons totally unrelated to it.

Suppose I test the hypothesis that plants need water to germinate by subjecting some seeds to water and some to a lack of water. Maybe I find those without water don't germinate while those with water do. This seems to indicate the hypothesis is true, but suppose the seeds I planted without water were actually already totally dead. I'd be getting the results I expected for reasons totally different from my hypothesis.

The second is that I might get the results I expect and thus think my hypothesis is supported, but someone else, undertaking the same study in a different place or time, might get results denying it.

Your presentation will have an interactive component. Will we have to handle an object? Get out of our chairs? The actual exploration we will be undertaking concerns a simple everyday example, playing cards. No plants or animals will be endangered by the exercise.

How can we learn more about you? Through my personal website, kaconjour.com, or the Southern Oregon Climate Action Network website, soclimate.org.

And you host a program of classical music featuring selections from your personal library? Yes, "A Musical Meander" broadcasts Saturdays from 5 to 7 p.m. on the JPR Classics and News Service. In Ashland, turn to KSOR 90.1 and KSRG 88.3 or www.ijpr.org.